net: mvpp2: disable force link UP during port init procedure

Force link UP can be enabled by bootloader during tftpboot
and breaks NFS support.
Force link UP disabled during port init procedure.

Fixes: f84bf386

 ("net: mvpp2: initialize the GoP")
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/r/1608216735-14501-1-git-send-email-stefanc@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>